The present invention relates to an assembly for dispensing a semi-liquid substance or a gel.
The assembly of the invention is of the type including an airless pump. The receptacle containing the substance to be dispensed must therefore be of variable volume, i.e. its volume must be capable of decreasing as the substance is dispensed. In known manner, the variable-volume receptacle may be a rigid receptacle containing a follower piston that moves towards the pump as dispensing progresses, or a receptacle having a deformable wall made of a flexible plastics material or folded concertina-like. The pump is generally fixed to the pump body by being crimped onto a crimping dish or a plate. The pump includes a hollow projecting stem which serves both to actuate the pump and also to discharge the substance. The pump is actuated via a dispensing head by pushing in the projecting stem, the dispensing head containing dispensing channels that open out to the outside. That type of dispensing assembly is generally used for liquid or substances of little viscosity, and the substance is sprayed from the dispensing head.
For viscous substances, such as deodorants, an assembly is generally used in which the substance is in a receptacle provided with a follower piston, and in which the piston is pushed by means of a knurled wheel mechanism to discharge the substance. That system suffers from drawbacks:
firstly, the substance is not protected from ambient air during storage because, although the receptacle is closed with a lid, the lid is not airtight so that, in order to protect the substance during storage, it is necessary to put a protective film over the dispensing head; and
secondly, applying the substance requires two successive actions: actuating the knurled wheel and applying the substance.
The present invention relates to a dispenser assembly which makes it possible to use a pump for dispensing a fluid substance that is relatively viscous, i.e. that is in the form of a paste or of a gel, and which offers the advantage of requiring only a single action in order both to dispense and to apply the substance.
In the invention, a receptacle of variable volume is used that is provided with a pump associated with a dispensing head, and that makes it possible, with a single action, both to actuate the pump and to apply the substance, the pressure exerted by the user on the dispensing head during application, e.g. as it rubs on the skin, actuating the pump and causing the substance to be dispensed.
The present invention provides an assembly for dispensing a viscous fluid substance, in particular a paste or a gel, said assembly including a receptacle of variable volume containing the substance to be dispensed, dispensing taking place by means of an airless pump which comprises a pump body that communicates freely with the inside of the receptacle, and an outlet member via which the substance is discharged, said dispensing being implemented by means of a dispensing head provided with dispensing channels which are open to the outside and which are fed via the outlet member of the pump, said assembly being characterized by the fact that the dispensing head comprises firstly a backplate which is provided with assembly means for assembling it onto the pump outlet member and with an opening facing said pump outlet member, and secondly an applicator element which is secured to the backplate, which is disposed on the other side of the backplate from the receptacle, and which is provided with openings opening towards the outside, the dispensing channels which connect the pump outlet member to the openings in the applicator element being disposed between the backplate and said applicator element.
Under these conditions, when the applicator element is pressed against the skin, the pump is simultaneously actuated because the applicator element and the backplate are secured together. The substance is discharged through the openings in the applicator element by means of the channels that connect the outlet member of the pump to the openings in applicator element. In the invention, the pressure exerted on the dispensing head during application is used to actuate the pump.
Advantageously, the pump is a pump having a projecting stem, said stem being hollow to constitute an outlet member through which the substance is discharged, and being capable of being pushed towards the pump body to dispense said substance.
In the invention, the dispensing channels may be provided in the backplate or in the support, or also in part in that surface of the backplate which faces towards the applicator element and in part in that surface of the applicator element which faces towards the backplate, the facing surfaces of the backplate and of the applicator being complementary and forming channels when they are disposed one against the other.
Preferably, the various channels connecting the pump outlet to the various openings of the applicator element have cross-sections that vary as a function of the lengths of the various channels, i.e. as a function of the relative disposition of the various openings and of the outlet of the pump, so as to obtain, for all of the openings in the applicator element, flow rates of substance to be dispensed that are substantially equal.
In the invention, the backplate is advantageously a plate that is generally plane or slightly convex. It is advantageously provided with an opening surrounded by a sleeve facing towards the receptacle, and serving to secure to the pump stem.
In a first embodiment of the invention, the applicator element includes a plate that is plane or slightly convex and that is provided with uniformly-distributed openings. During use, the user rubs the applicator against the skin, and, so doing, simultaneously actuates the pump and distributes the substance to be dispensed that is discharged via the openings provided in the plate.
In a second embodiment, the applicator element is provided with a trough whose end wall is provided with openings and whose side walls are fixed to at least one roller whose axis, embodied by a pin, is perpendicular to the axis of the receptacle, said roller being provided with radial blades, the axis of the roller being disposed so that the edges of the radial blades rub against the end wall of the trough and can take up the substance dispensed via the openings disposed in the end wall of the trough. The edges of each of the blades is preferably cut to a regular pattern, e.g. to a sinusoidal pattern.
In a third embodiment of the invention, the applicator element comprises a support provided with recesses in the form of spherical cups in which balls are disposed, openings being provided in the support at the bottoms of the recesses.
In a fourth embodiment of the invention, the applicator element comprises a comb made up of a base plate from which teeth project outwardly, each of the teeth being in the form of a prism of triangular or trapezium shaped right cross-section. Preferably, each of the teeth is formed of a prism having a cross-section that is isosceles trapezium shaped, and the edges of the teeth are disposed to be mutually parallel. The openings may be disposed in the base plate between the teeth but they preferably open out in the side walls of the teeth-forming prisms.
As indicated above, the backplate and applicator element assembly constitutes the system for actuating the pump. To this end, the assembly is fixed to the pump stem and it is suitable for being moved in linear translation when the user presses on the applicator element. The applicator element is generally provided with a skirt that is suitable for sliding on the side wall of the receptacle.
The pump used in the invention may be any airless pump. Preferably a xe2x80x9csoftxe2x80x9d pump is used that is actuated at a pressure less than 1 kilogram per square meter (kg/m2).
Since the pump used in the dispenser assembly of the invention is airless, i.e. it has no air intake, the receptacle containing the substance to be dispensed is of variable volume, as explained above. It may be constituted by a bag having deformable walls which deform as the substance is dispensed, or by a receptacle with concertina-like folds that close up. Preferably, it is constituted by rigid casing in which a follower piston is mounted to slide in leaktight manner, which follower piston moves closer to the pump as the substance is dispensed. The end of the rigid casing may be open or it may be closed, an opening then being provided to enable air to enter.
The dispensing head of the assembly of the present invention is preferably covered with a cap.
In order for the invention to be better understood, a description follows by way of non-limiting example of embodiments shown in the accompanying drawings.